/* ----------------------------------------------------------------------
 * Project:      CMSIS DSP Library
 * Title:        arm_cmplx_mag_f32.c
 * Description:  Floating-point complex magnitude
 *
 * $Date:        18. March 2019
 * $Revision:    V1.6.0
 *
 * Target Processor: Cortex-M cores
 * -------------------------------------------------------------------- */
/*
 * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "arm_math.h"

/**
  @ingroup groupCmplxMath
 */

/**
  @defgroup cmplx_mag Complex Magnitude

  Computes the magnitude of the elements of a complex data vector.

  The <code>pSrc</code> points to the source data and
  <code>pDst</code> points to the where the result should be written.
  <code>numSamples</code> specifies the number of complex samples
  in the input array and the data is stored in an interleaved fashion
  (real, imag, real, imag, ...).
  The input array has a total of <code>2*numSamples</code> values;
  the output array has a total of <code>numSamples</code> values.

  The underlying algorithm is used:

  <pre>
  for (n = 0; n < numSamples; n++) {
      pDst[n] = sqrt(pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2);
  }
  </pre>

  There are separate functions for floating-point, Q15, and Q31 data types.
 */

/**
  @addtogroup cmplx_mag
  @{
 */

/**
  @brief         Floating-point complex magnitude.
  @param[in]     pSrc        points to input vector
  @param[out]    pDst        points to output vector
  @param[in]     numSamples  number of samples in each vector
  @return        none
 */

#if defined(ARM_MATH_NEON) && !defined(ARM_MATH_AUTOVECTORIZE)
#include "arm_vec_math.h"
#endif

#if defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE)

#include "arm_helium_utils.h"


void arm_cmplx_mag_f32(
	const float32_t *pSrc,
	float32_t *pDst,
	uint32_t numSamples)
{
	int32_t blockSize = numSamples;  /* loop counters */
	uint32_t  blkCnt;           /* loop counters */
	f32x4x2_t vecSrc;
	f32x4_t sum;
	float32_t real, imag;                      /* Temporary variables to hold input values */

	/* Compute 4 complex samples at a time */
	blkCnt = blockSize >> 2;
	while (blkCnt > 0U) {
		q31x4_t newtonStartVec;
		f32x4_t sumHalf, invSqrt;

		vecSrc = vld2q(pSrc);
		pSrc += 8;
		sum = vmulq(vecSrc.val[0], vecSrc.val[0]);
		sum = vfmaq(sum, vecSrc.val[1], vecSrc.val[1]);

		/*
		 * inlined Fast SQRT using inverse SQRT newton-raphson method
		 */

		/* compute initial value */
		newtonStartVec = vdupq_n_s32(INVSQRT_MAGIC_F32) - vshrq((q31x4_t) sum, 1);
		sumHalf = sum * 0.5f;
		/*
		 * compute 3 x iterations
		 *
		 * The more iterations, the more accuracy.
		 * If you need to trade a bit of accuracy for more performance,
		 * you can comment out the 3rd use of the macro.
		 */
		INVSQRT_NEWTON_MVE_F32(invSqrt, sumHalf, (f32x4_t) newtonStartVec);
		INVSQRT_NEWTON_MVE_F32(invSqrt, sumHalf, invSqrt);
		INVSQRT_NEWTON_MVE_F32(invSqrt, sumHalf, invSqrt);
		/*
		 * set negative values to 0
		 */
		invSqrt = vdupq_m(invSqrt, 0.0f, vcmpltq(invSqrt, 0.0f));
		/*
		 * sqrt(x) = x * invSqrt(x)
		 */
		sum = vmulq(sum, invSqrt);
		vst1q(pDst, sum);
		pDst += 4;
		/*
		 * Decrement the blockSize loop counter
		 */
		blkCnt--;
	}
	/*
	 * tail
	 */
	blkCnt = blockSize & 3;
	while (blkCnt > 0U) {
		/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */

		real = *pSrc++;
		imag = *pSrc++;

		/* store result in destination buffer. */
		arm_sqrt_f32((real * real) + (imag * imag), pDst++);

		/* Decrement loop counter */
		blkCnt--;
	}
}

#else
void arm_cmplx_mag_f32(
	const float32_t *pSrc,
	float32_t *pDst,
	uint32_t numSamples)
{
	uint32_t blkCnt;                               /* loop counter */
	float32_t real, imag;                      /* Temporary variables to hold input values */

#if defined(ARM_MATH_NEON) && !defined(ARM_MATH_AUTOVECTORIZE)

	float32x4x2_t vecA;
	float32x4_t vRealA;
	float32x4_t vImagA;
	float32x4_t vMagSqA;

	float32x4x2_t vecB;
	float32x4_t vRealB;
	float32x4_t vImagB;
	float32x4_t vMagSqB;

	/* Loop unrolling: Compute 8 outputs at a time */
	blkCnt = numSamples >> 3;

	while (blkCnt > 0U) {
		/* out = sqrt((real * real) + (imag * imag)) */

		vecA = vld2q_f32(pSrc);
		pSrc += 8;

		vecB = vld2q_f32(pSrc);
		pSrc += 8;

		vRealA = vmulq_f32(vecA.val[0], vecA.val[0]);
		vImagA = vmulq_f32(vecA.val[1], vecA.val[1]);
		vMagSqA = vaddq_f32(vRealA, vImagA);

		vRealB = vmulq_f32(vecB.val[0], vecB.val[0]);
		vImagB = vmulq_f32(vecB.val[1], vecB.val[1]);
		vMagSqB = vaddq_f32(vRealB, vImagB);

		/* Store the result in the destination buffer. */
		vst1q_f32(pDst, __arm_vec_sqrt_f32_neon(vMagSqA));
		pDst += 4;

		vst1q_f32(pDst, __arm_vec_sqrt_f32_neon(vMagSqB));
		pDst += 4;

		/* Decrement the loop counter */
		blkCnt--;
	}

	blkCnt = numSamples & 7;

#else

#if defined (ARM_MATH_LOOPUNROLL) && !defined(ARM_MATH_AUTOVECTORIZE)

	/* Loop unrolling: Compute 4 outputs at a time */
	blkCnt = numSamples >> 2U;

	while (blkCnt > 0U) {
		/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */

		real = *pSrc++;
		imag = *pSrc++;

		/* store result in destination buffer. */
		arm_sqrt_f32((real * real) + (imag * imag), pDst++);

		real = *pSrc++;
		imag = *pSrc++;
		arm_sqrt_f32((real * real) + (imag * imag), pDst++);

		real = *pSrc++;
		imag = *pSrc++;
		arm_sqrt_f32((real * real) + (imag * imag), pDst++);

		real = *pSrc++;
		imag = *pSrc++;
		arm_sqrt_f32((real * real) + (imag * imag), pDst++);

		/* Decrement loop counter */
		blkCnt--;
	}

	/* Loop unrolling: Compute remaining outputs */
	blkCnt = numSamples % 0x4U;

#else

	/* Initialize blkCnt with number of samples */
	blkCnt = numSamples;

#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
#endif /* #if defined(ARM_MATH_NEON) */

	while (blkCnt > 0U) {
		/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */

		real = *pSrc++;
		imag = *pSrc++;

		/* store result in destination buffer. */
		arm_sqrt_f32((real * real) + (imag * imag), pDst++);

		/* Decrement loop counter */
		blkCnt--;
	}

}
#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */

/**
  @} end of cmplx_mag group
 */
